DEADSOFTWARE

Исправлен экспорт полей и экспорт для "только чтения"
[dsw-obn.git] / oberon.c
index 440364361e45956f86091d3022fd50b3099f1026..b56a458a6c1e979a743c9d4139b5df3044f1cdc3 100644 (file)
--- a/oberon.c
+++ b/oberon.c
@@ -3,6 +3,7 @@
 #include <stdarg.h>
 #include <ctype.h>
 #include <string.h>
+#include <assert.h>
 
 #include "oberon.h"
 #include "generator.h"
@@ -38,7 +39,21 @@ enum {
        MOD,
        AND,
        NOT,
-       PROCEDURE
+       PROCEDURE,
+       COMMA,
+       RETURN,
+       CONST,
+       TYPE,
+       ARRAY,
+       OF,
+       LBRACE,
+       RBRACE,
+       RECORD,
+       POINTER,
+       TO,
+       UPARROW,
+       NIL,
+       IMPORT
 };
 
 // =======================================================================
@@ -60,55 +75,150 @@ oberon_error(oberon_context_t * ctx, const char * fmt, ...)
        exit(1);
 }
 
+static oberon_type_t *
+oberon_new_type_ptr(int class)
+{
+       oberon_type_t * x = malloc(sizeof *x);
+       memset(x, 0, sizeof *x);
+       x -> class = class;
+       return x;
+}
+
+static oberon_type_t *
+oberon_new_type_integer(int size)
+{
+       oberon_type_t * x;
+       x = oberon_new_type_ptr(OBERON_TYPE_INTEGER);
+       x -> size = size;
+       return x;
+}
+
+static oberon_type_t *
+oberon_new_type_boolean(int size)
+{
+       oberon_type_t * x;
+       x = oberon_new_type_ptr(OBERON_TYPE_BOOLEAN);
+       x -> size = size;
+       return x;
+}
+
 // =======================================================================
 //   TABLE
 // ======================================================================= 
 
-static oberon_type_t *
-oberon_find_type(oberon_context_t * ctx, char * name)
+static oberon_scope_t *
+oberon_open_scope(oberon_context_t * ctx)
 {
-       oberon_type_t * x = ctx -> types;
-       while(x -> next && strcmp(x -> next -> name, name) != 0)
+       oberon_scope_t * scope = calloc(1, sizeof *scope);
+       oberon_object_t * list = calloc(1, sizeof *list);
+
+       scope -> ctx = ctx;
+       scope -> list = list;
+       scope -> up = ctx -> decl;
+
+       if(scope -> up)
        {
-               x = x -> next;
+               scope -> parent = scope -> up -> parent;
+               scope -> local = scope -> up -> local;
        }
 
-       return x -> next;
+       ctx -> decl = scope;
+       return scope;
+}
+
+static void
+oberon_close_scope(oberon_scope_t * scope)
+{
+       oberon_context_t * ctx = scope -> ctx;
+       ctx -> decl = scope -> up;
 }
 
-static oberon_var_t *
-oberon_find_var(oberon_context_t * ctx, char * name)
+static oberon_object_t *
+oberon_define_object(oberon_scope_t * scope, char * name, int class, int export, int read_only)
 {
-       oberon_var_t * x = ctx -> mod -> vars;
+       oberon_object_t * x = scope -> list;
        while(x -> next && strcmp(x -> next -> name, name) != 0)
        {
                x = x -> next;
        }
 
-       return x -> next;
+       if(x -> next)
+       {
+               oberon_error(scope -> ctx, "already defined");
+       }
+
+       oberon_object_t * newvar = malloc(sizeof *newvar);
+       memset(newvar, 0, sizeof *newvar);
+       newvar -> name = name;
+       newvar -> class = class;
+       newvar -> export = export;
+       newvar -> read_only = read_only;
+       newvar -> local = scope -> local;
+       newvar -> parent = scope -> parent;
+       newvar -> module = scope -> ctx -> mod;
+
+       x -> next = newvar;
+
+       return newvar;
 }
 
-static void
-oberon_define_var(oberon_context_t * ctx, char * name, oberon_type_t * type)
+static oberon_object_t *
+oberon_find_object_in_list(oberon_object_t * list, char * name)
 {
-       oberon_var_t * x = ctx -> mod -> vars;
+       oberon_object_t * x = list;
        while(x -> next && strcmp(x -> next -> name, name) != 0)
        {
                x = x -> next;
        }
+       return x -> next;
+}
 
-       if(x -> next)
+static oberon_object_t *
+oberon_find_object(oberon_scope_t * scope, char * name, int check_it)
+{
+       oberon_object_t * result = NULL;
+
+       oberon_scope_t * s = scope;
+       while(result == NULL && s != NULL)
        {
-               oberon_error(ctx, "already defined");
+               result = oberon_find_object_in_list(s -> list, name);
+               s = s -> up;
        }
 
-       oberon_var_t * newvar = malloc(sizeof *newvar);
-       memset(newvar, 0, sizeof *newvar);
-       newvar -> name = name;
-       newvar -> type = type;
-       oberon_generator_init_var(ctx, newvar);
+       if(check_it && result == NULL)
+       {
+               oberon_error(scope -> ctx, "undefined ident %s", name);
+       }
 
-       x -> next = newvar;
+       return result;
+}
+
+static oberon_object_t *
+oberon_find_field(oberon_context_t * ctx, oberon_type_t * rec, char * name)
+{
+       oberon_object_t * x = rec -> decl;
+       for(int i = 0; i < rec -> num_decl; i++)
+       {
+               if(strcmp(x -> name, name) == 0)
+               {
+                       return x;
+               }
+               x = x -> next;
+       }
+
+       oberon_error(ctx, "field not defined");
+
+       return NULL;
+}
+
+static oberon_object_t *
+oberon_define_type(oberon_scope_t * scope, char * name, oberon_type_t * type, int export)
+{
+       oberon_object_t * id;
+       id = oberon_define_object(scope, name, OBERON_CLASS_TYPE, export, 0);
+       id -> type = type;
+       oberon_generator_init_type(scope -> ctx, type);
+       return id;
 }
 
 // =======================================================================
@@ -193,6 +303,46 @@ oberon_read_ident(oberon_context_t * ctx)
        {
                ctx -> token = PROCEDURE;
        }
+       else if(strcmp(ident, "RETURN") == 0)
+       {
+               ctx -> token = RETURN;
+       }
+       else if(strcmp(ident, "CONST") == 0)
+       {
+               ctx -> token = CONST;
+       }
+       else if(strcmp(ident, "TYPE") == 0)
+       {
+               ctx -> token = TYPE;
+       }
+       else if(strcmp(ident, "ARRAY") == 0)
+       {
+               ctx -> token = ARRAY;
+       }
+       else if(strcmp(ident, "OF") == 0)
+       {
+               ctx -> token = OF;
+       }
+       else if(strcmp(ident, "RECORD") == 0)
+       {
+               ctx -> token = RECORD;
+       }
+       else if(strcmp(ident, "POINTER") == 0)
+       {
+               ctx -> token = POINTER;
+       }
+       else if(strcmp(ident, "TO") == 0)
+       {
+               ctx -> token = TO;
+       }
+       else if(strcmp(ident, "NIL") == 0)
+       {
+               ctx -> token = NIL;
+       }
+       else if(strcmp(ident, "IMPORT") == 0)
+       {
+               ctx -> token = IMPORT;
+       }
 }
 
 static void
@@ -313,6 +463,22 @@ oberon_read_symbol(oberon_context_t * ctx)
                        ctx -> token = NOT;
                        oberon_get_char(ctx);
                        break;
+               case ',':
+                       ctx -> token = COMMA;
+                       oberon_get_char(ctx);
+                       break;
+               case '[':
+                       ctx -> token = LBRACE;
+                       oberon_get_char(ctx);
+                       break;
+               case ']':
+                       ctx -> token = RBRACE;
+                       oberon_get_char(ctx);
+                       break;
+               case '^':
+                       ctx -> token = UPARROW;
+                       oberon_get_char(ctx);
+                       break;
                default:
                        oberon_error(ctx, "invalid char");
                        break;
@@ -347,6 +513,8 @@ static void oberon_expect_token(oberon_context_t * ctx, int token);
 static oberon_expr_t * oberon_expr(oberon_context_t * ctx);
 static void oberon_assert_token(oberon_context_t * ctx, int token);
 static char * oberon_assert_ident(oberon_context_t * ctx);
+static void oberon_type(oberon_context_t * ctx, oberon_type_t ** type);
+static oberon_item_t * oberon_const_expr(oberon_context_t * ctx);
 
 static oberon_expr_t *
 oberon_new_operator(int op, oberon_type_t * result, oberon_expr_t * left, oberon_expr_t * right)
@@ -357,6 +525,7 @@ oberon_new_operator(int op, oberon_type_t * result, oberon_expr_t * left, oberon
 
        operator -> is_item = 0;
        operator -> result = result;
+       operator -> read_only = 1;
        operator -> op = op;
        operator -> left = left;
        operator -> right = right;
@@ -365,7 +534,7 @@ oberon_new_operator(int op, oberon_type_t * result, oberon_expr_t * left, oberon
 }
 
 static oberon_expr_t *
-oberon_new_item(int mode, oberon_type_t * result)
+oberon_new_item(int mode, oberon_type_t * result, int read_only)
 {
        oberon_item_t * item;
         item = malloc(sizeof *item);
@@ -373,6 +542,7 @@ oberon_new_item(int mode, oberon_type_t * result)
 
        item -> is_item = 1;
        item -> result = result;
+       item -> read_only = read_only;
        item -> mode = mode;
 
        return (oberon_expr_t *)item;
@@ -412,376 +582,1694 @@ oberon_make_unary_op(oberon_context_t * ctx, int token, oberon_expr_t * a)
        return expr;
 }
 
-static oberon_expr_t *
-oberon_factor(oberon_context_t * ctx)
+static void
+oberon_expr_list(oberon_context_t * ctx, int * num_expr, oberon_expr_t ** first, int const_expr)
 {
-       char * name;
-       oberon_var_t * var;
-       oberon_expr_t * expr;
+       oberon_expr_t * last;
 
-       switch(ctx -> token)
+       *num_expr = 1;
+       *first = last = oberon_expr(ctx);
+       while(ctx -> token == COMMA)
        {
-               case IDENT:
-                       name = oberon_assert_ident(ctx);
-                       var = oberon_find_var(ctx, name);
-                       if(var == NULL)
-                       {
-                               oberon_error(ctx, "undefined variable %s", name);
-                       }
-                       expr = oberon_new_item(MODE_VAR, var -> type);
-                       expr -> item.var = var;
-                       break;
-               case INTEGER:
-                       expr = oberon_new_item(MODE_INTEGER, ctx -> int_type);
-                       expr -> item.integer = ctx -> integer;
-                       oberon_assert_token(ctx, INTEGER);
-                       break;
-               case TRUE:
-                       expr = oberon_new_item(MODE_BOOLEAN, ctx -> bool_type);
-                       expr -> item.boolean = 1;
-                       oberon_assert_token(ctx, TRUE);
-                       break;
-               case FALSE:
-                       expr = oberon_new_item(MODE_BOOLEAN, ctx -> bool_type);
-                       expr -> item.boolean = 0;
-                       oberon_assert_token(ctx, FALSE);
-                       break;
-               case LPAREN:
-                       oberon_assert_token(ctx, LPAREN);
-                       expr = oberon_expr(ctx);
-                       oberon_assert_token(ctx, RPAREN);
-                       break;
-               case NOT:
-                       oberon_assert_token(ctx, NOT);
-                       expr = oberon_factor(ctx);
-                       expr = oberon_make_unary_op(ctx, NOT, expr);
-                       break;
-               default:
-                       oberon_error(ctx, "invalid expression");
-       }
+               oberon_assert_token(ctx, COMMA);
+               oberon_expr_t * current;
 
-       return expr;
-}
+               if(const_expr)
+               {
+                       current = (oberon_expr_t *) oberon_const_expr(ctx);
+               }
+               else
+               {
+                       current = oberon_expr(ctx);
+               }
 
-/*
- * oberon_autocast_binary_op автоматически переобразовывеат тип по след. правилам:
- *   1. Классы обоих типов должны быть одинаковы
- *   2. В качестве результата должен быть выбран больший тип.
- *   3. Если размер результат не должен быть меньше чем базовый int
- */
+               last -> next = current;
+               last = current;
+               *num_expr += 1;
+       }
+}
 
-static void
-oberon_autocast_binary_op(oberon_context_t * ctx, oberon_type_t * a, oberon_type_t * b, oberon_type_t ** result)
+static oberon_expr_t *
+oberon_autocast_to(oberon_context_t * ctx, oberon_expr_t * expr, oberon_type_t * pref)
 {
-       if((a -> class) != (b -> class))
+       if(pref -> class != expr -> result -> class)
        {
                oberon_error(ctx, "incompatible types");
        }
 
-       if((a -> size) > (b -> size))
+       if(pref -> class == OBERON_TYPE_INTEGER)
        {
-               *result = a;
+               if(expr -> result -> class > pref -> class)
+               {
+                       oberon_error(ctx, "incompatible size");
+               }
        }
-       else
+       else if(pref -> class == OBERON_TYPE_RECORD)
        {
-               *result = b;
+               if(expr -> result != pref)
+               {
+                       printf("oberon_autocast_to: rec %p != %p\n", expr -> result, pref);
+                       oberon_error(ctx, "incompatible record types");
+               }
        }
-
-       if(((*result) -> class) == OBERON_TYPE_INTEGER)
+       else if(pref -> class == OBERON_TYPE_POINTER)
        {
-               if(((*result) -> size) < (ctx -> int_type -> size))
+               if(expr -> result -> base != pref -> base)
                {
-                       *result = ctx -> int_type;
+                       if(expr -> result -> base -> class != OBERON_TYPE_VOID)
+                       {
+                               oberon_error(ctx, "incompatible pointer types");
+                       }
                }
        }
 
-       /* TODO: cast types */
+       // TODO cast
+
+       return expr;
 }
 
-#define ITMAKESBOOLEAN(x) \
-       (((x) >= EQUAL && (x) <= GEQ) || ((x) == OR) || ((x) == AND))
+static void
+oberon_autocast_call(oberon_context_t * ctx, oberon_expr_t * desig)
+{
+       if(desig -> is_item == 0)
+       {
+               oberon_error(ctx, "expected item");
+       }
 
-#define ITUSEONLYINTEGER(x) \
-       ((x) >= LESS && (x) <= GEQ)
+       if(desig -> item.mode != MODE_CALL)
+       {
+               oberon_error(ctx, "expected mode CALL");
+       }
 
-#define ITUSEONLYBOOLEAN(x) \
-       (((x) == OR) || ((x) == AND))
+       if(desig -> item.var -> type -> class != OBERON_TYPE_PROCEDURE)
+       {
+               oberon_error(ctx, "only procedures can be called");
+       }
 
-static oberon_expr_t *
-oberon_make_bin_op(oberon_context_t * ctx, int token, oberon_expr_t * a, oberon_expr_t * b)
-{
-       oberon_expr_t * expr;
-       oberon_type_t * result;
+       oberon_type_t * fn = desig -> item.var -> type;
+       int num_args = desig -> item.num_args;
+       int num_decl = fn -> num_decl;
 
-       oberon_autocast_binary_op(ctx, a -> result, b -> result, &result);
+       if(num_args < num_decl)
+       {
+               oberon_error(ctx, "too few arguments");
+       }
+       else if(num_args > num_decl)
+       {
+               oberon_error(ctx, "too many arguments");
+       }
 
-       if(ITMAKESBOOLEAN(token))
+       oberon_expr_t * arg = desig -> item.args;
+       oberon_object_t * param = fn -> decl;
+       for(int i = 0; i < num_args; i++)
        {
-               if(ITUSEONLYINTEGER(token))
+               if(param -> class == OBERON_CLASS_VAR_PARAM)
                {
-                       if(a -> result -> class != OBERON_TYPE_INTEGER
-                               && b -> result -> class != OBERON_TYPE_INTEGER)
+                       if(arg -> is_item)
                        {
-                               oberon_error(ctx, "used only with integer types");
+                               switch(arg -> item.mode)
+                               {
+                                       case MODE_VAR:
+                                       case MODE_INDEX:
+                                       case MODE_FIELD:
+                                       // Допустимо разыменование?
+                                       //case MODE_DEREF:
+                                               break;
+                                       default:
+                                               oberon_error(ctx, "var-parameter accept only variables");
+                                               break;
+                               }
                        }
                }
-               else if(ITUSEONLYBOOLEAN(token))
-               {
-                       if(a -> result -> class != OBERON_TYPE_BOOLEAN
-                               && b -> result -> class != OBERON_TYPE_BOOLEAN)
+               oberon_autocast_to(ctx, arg, param -> type);
+               arg = arg -> next;
+               param = param -> next;
+       }
+}
+
+static oberon_expr_t *
+oberon_make_call_func(oberon_context_t * ctx, oberon_object_t * proc, int num_args, oberon_expr_t * list_args)
+{
+       switch(proc -> class)
+       {
+               case OBERON_CLASS_PROC:
+                       if(proc -> class != OBERON_CLASS_PROC)
                        {
-                               oberon_error(ctx, "used only with boolean type");
+                               oberon_error(ctx, "not a procedure");
                        }
-               }
+                       break;
+               case OBERON_CLASS_VAR:
+               case OBERON_CLASS_VAR_PARAM:
+               case OBERON_CLASS_PARAM:
+                       if(proc -> type -> class != OBERON_TYPE_PROCEDURE)
+                       {
+                               oberon_error(ctx, "not a procedure");
+                       }
+                       break;
+               default:
+                       oberon_error(ctx, "not a procedure");
+                       break;
+       }
 
-               if(token == EQUAL)
-               {
-                       expr = oberon_new_operator(OP_EQ, result, a, b);
-               }
-               else if(token == NEQ)
-               {
-                       expr = oberon_new_operator(OP_NEQ, result, a, b);
-               }
-               else if(token == LESS)
-               {
-                       expr = oberon_new_operator(OP_LSS, result, a, b);
-               }
-               else if(token == LEQ)
-               {
-                       expr = oberon_new_operator(OP_LEQ, result, a, b);
-               }
-               else if(token == GREAT)
+       oberon_expr_t * call;
+
+       if(proc -> sysproc)
+       {
+               if(proc -> genfunc == NULL)
                {
-                       expr = oberon_new_operator(OP_GRT, result, a, b);
+                       oberon_error(ctx, "not a function-procedure");
                }
-               else if(token == GEQ)
+
+               call = proc -> genfunc(ctx, num_args, list_args);
+       }
+       else
+       {
+               if(proc -> type -> base -> class == OBERON_TYPE_VOID)
                {
-                       expr = oberon_new_operator(OP_GEQ, result, a, b);
+                       oberon_error(ctx, "attempt to call procedure in expression");
                }
-               else if(token == OR)
+
+               call = oberon_new_item(MODE_CALL, proc -> type -> base, 1);
+               call -> item.var = proc;
+               call -> item.num_args = num_args;
+               call -> item.args = list_args;
+               oberon_autocast_call(ctx, call);
+       }
+
+       return call;
+}
+
+static void
+oberon_make_call_proc(oberon_context_t * ctx, oberon_object_t * proc, int num_args, oberon_expr_t * list_args)
+{
+       switch(proc -> class)
+       {
+               case OBERON_CLASS_PROC:
+                       if(proc -> class != OBERON_CLASS_PROC)
+                       {
+                               oberon_error(ctx, "not a procedure");
+                       }
+                       break;
+               case OBERON_CLASS_VAR:
+               case OBERON_CLASS_VAR_PARAM:
+               case OBERON_CLASS_PARAM:
+                       if(proc -> type -> class != OBERON_TYPE_PROCEDURE)
+                       {
+                               oberon_error(ctx, "not a procedure");
+                       }
+                       break;
+               default:
+                       oberon_error(ctx, "not a procedure");
+                       break;
+       }
+
+       if(proc -> sysproc)
+       {
+               if(proc -> genproc == NULL)
                {
-                       expr = oberon_new_operator(OP_LOGIC_OR, result, a, b);
+                       oberon_error(ctx, "requres non-typed procedure");
                }
-               else if(token == AND)
+
+               proc -> genproc(ctx, num_args, list_args);
+       }
+       else
+       {
+               if(proc -> type -> base -> class != OBERON_TYPE_VOID)
                {
-                       expr = oberon_new_operator(OP_LOGIC_AND, result, a, b);
-               }
-               else
-               {
-                       oberon_error(ctx, "oberon_make_bin_op: bool wat");
+                       oberon_error(ctx, "attempt to call function as non-typed procedure");
                }
+
+               oberon_expr_t * call;
+               call = oberon_new_item(MODE_CALL, proc -> type -> base, 1);
+               call -> item.var = proc;
+               call -> item.num_args = num_args;
+               call -> item.args = list_args;
+               oberon_autocast_call(ctx, call);
+               oberon_generate_call_proc(ctx, call);
        }
-       else
+}
+
+#define ISEXPR(x) \
+       (((x) == PLUS) \
+       || ((x) == MINUS) \
+       || ((x) == IDENT) \
+       || ((x) == INTEGER) \
+       || ((x) == LPAREN) \
+       || ((x) == NOT) \
+       || ((x) == TRUE) \
+       || ((x) == FALSE))
+
+static oberon_expr_t *
+oberno_make_dereferencing(oberon_context_t * ctx, oberon_expr_t * expr)
+{
+       if(expr -> result -> class != OBERON_TYPE_POINTER)
        {
-               if(token == PLUS)
+               oberon_error(ctx, "not a pointer");
+       }
+
+       assert(expr -> is_item);
+
+       oberon_expr_t * selector;
+       selector = oberon_new_item(MODE_DEREF, expr -> result -> base, expr -> read_only);
+       selector -> item.parent = (oberon_item_t *) expr;
+
+       return selector;
+}
+
+static oberon_expr_t *
+oberon_make_array_selector(oberon_context_t * ctx, oberon_expr_t * desig, oberon_expr_t * index)
+{
+       if(desig -> result -> class == OBERON_TYPE_POINTER)
+       {
+               desig = oberno_make_dereferencing(ctx, desig);
+       }
+
+       assert(desig -> is_item);
+
+       if(desig -> result -> class != OBERON_TYPE_ARRAY)
+       {
+               oberon_error(ctx, "not array");
+       }
+
+       oberon_type_t * base;
+       base = desig -> result -> base;
+
+       if(index -> result -> class != OBERON_TYPE_INTEGER)
+       {
+               oberon_error(ctx, "index must be integer");
+       }
+
+       // Статическая проверка границ массива
+       if(index -> is_item)
+       {
+               if(index -> item.mode == MODE_INTEGER)
                {
-                       expr = oberon_new_operator(OP_ADD, result, a, b);
+                       int arr_size = desig -> result -> size;
+                       int index_int = index -> item.integer;
+                       if(index_int < 0 || index_int > arr_size - 1)
+                       {
+                               oberon_error(ctx, "not in range (dimension size 0..%i)", arr_size - 1);
+                       }
                }
-               else if(token == MINUS)
+       }
+
+       oberon_expr_t * selector;
+       selector = oberon_new_item(MODE_INDEX, base, desig -> read_only);
+       selector -> item.parent = (oberon_item_t *) desig;
+       selector -> item.num_args = 1;
+       selector -> item.args = index;
+
+       return selector;
+}
+
+static oberon_expr_t *
+oberon_make_record_selector(oberon_context_t * ctx, oberon_expr_t * expr, char * name)
+{
+       if(expr -> result -> class == OBERON_TYPE_POINTER)
+       {
+               expr = oberno_make_dereferencing(ctx, expr);
+       }
+
+       assert(expr -> is_item == 1);
+
+       if(expr -> result -> class != OBERON_TYPE_RECORD)
+       {
+               oberon_error(ctx, "not record");
+       }
+
+       oberon_type_t * rec = expr -> result;
+
+       oberon_object_t * field;
+       field = oberon_find_field(ctx, rec, name);
+
+       if(field -> export == 0)
+       {
+               if(field -> module != ctx -> mod)
                {
-                       expr = oberon_new_operator(OP_SUB, result, a, b);
+                       oberon_error(ctx, "field not exported");
                }
-               else if(token == STAR)
+       }
+
+       int read_only = 0;
+       if(field -> read_only)
+       {
+               if(field -> module != ctx -> mod)
                {
-                       expr = oberon_new_operator(OP_MUL, result, a, b);
+                       read_only = 1;
                }
-               else if(token == SLASH)
+       }
+
+       oberon_expr_t * selector;
+       selector = oberon_new_item(MODE_FIELD, field -> type, read_only);
+       selector -> item.var = field;
+       selector -> item.parent = (oberon_item_t *) expr;
+
+       return selector;
+}
+
+#define ISSELECTOR(x) \
+       (((x) == LBRACE) \
+       || ((x) == DOT) \
+       || ((x) == UPARROW))
+
+static oberon_object_t *
+oberon_qualident(oberon_context_t * ctx, char ** xname, int check)
+{
+       char * name;
+       oberon_object_t * x;
+
+       name = oberon_assert_ident(ctx);
+       x = oberon_find_object(ctx -> decl, name, check);
+
+       if(x != NULL)
+       {
+               if(x -> class == OBERON_CLASS_MODULE)
                {
-                       expr = oberon_new_operator(OP_DIV, result, a, b);
+                       oberon_assert_token(ctx, DOT);
+                       name = oberon_assert_ident(ctx);
+                       /* Наличие объектов в левых модулях всегда проверяется */
+                       x = oberon_find_object(x -> module -> decl, name, 1);
+
+                       if(x -> export == 0)
+                       {
+                               oberon_error(ctx, "not exported");
+                       }
                }
-               else if(token == DIV)
+       }
+
+       if(xname)
+       {
+               *xname = name;
+       }
+
+       return x;
+}
+
+static oberon_expr_t *
+oberon_designator(oberon_context_t * ctx)
+{
+       char * name;
+       oberon_object_t * var;
+       oberon_expr_t * expr;
+
+       var = oberon_qualident(ctx, NULL, 1);
+
+       int read_only = 0;
+       if(var -> read_only)
+       {
+               if(var -> module != ctx -> mod)
                {
-                       expr = oberon_new_operator(OP_DIV, result, a, b);
+                       read_only = 1;
                }
-               else if(token == MOD)
+       }
+
+       switch(var -> class)
+       {
+               case OBERON_CLASS_CONST:
+                       // TODO copy value
+                       expr = (oberon_expr_t *) var -> value;
+                       break;
+               case OBERON_CLASS_VAR:
+               case OBERON_CLASS_VAR_PARAM:
+               case OBERON_CLASS_PARAM:
+                       expr = oberon_new_item(MODE_VAR, var -> type, read_only);
+                       break;
+               case OBERON_CLASS_PROC:
+                       expr = oberon_new_item(MODE_VAR, var -> type, 1);
+                       break;
+               default:
+                       oberon_error(ctx, "invalid designator");
+                       break;
+       }
+       expr -> item.var = var;
+
+       while(ISSELECTOR(ctx -> token))
+       {
+               switch(ctx -> token)
                {
-                       expr = oberon_new_operator(OP_MOD, result, a, b);
+                       case DOT:
+                               oberon_assert_token(ctx, DOT);
+                               name = oberon_assert_ident(ctx);
+                               expr = oberon_make_record_selector(ctx, expr, name);
+                               break;
+                       case LBRACE:
+                               oberon_assert_token(ctx, LBRACE);
+                               int num_indexes = 0;
+                               oberon_expr_t * indexes = NULL;
+                               oberon_expr_list(ctx, &num_indexes, &indexes, 0);
+                               oberon_assert_token(ctx, RBRACE);
+
+                               for(int i = 0; i < num_indexes; i++)
+                               {
+                                       expr = oberon_make_array_selector(ctx, expr, indexes);
+                                       indexes = indexes -> next;
+                               }
+                               break;
+                       case UPARROW:
+                               oberon_assert_token(ctx, UPARROW);
+                               expr = oberno_make_dereferencing(ctx, expr);
+                               break;
+                       default:
+                               oberon_error(ctx, "oberon_designator: wat");
+                               break;
                }
-               else
+       }
+       return expr;
+}
+
+static oberon_expr_t *
+oberon_opt_func_parens(oberon_context_t * ctx, oberon_expr_t * expr)
+{
+       assert(expr -> is_item == 1);
+
+       /* Если есть скобки - значит вызов. Если нет, то передаём указатель. */
+       if(ctx -> token == LPAREN)
+       {
+               oberon_assert_token(ctx, LPAREN);
+
+               int num_args = 0;
+               oberon_expr_t * arguments = NULL;
+
+               if(ISEXPR(ctx -> token))
                {
-                       oberon_error(ctx, "oberon_make_bin_op: bin wat");
+                       oberon_expr_list(ctx, &num_args, &arguments, 0);
                }
+
+               expr = oberon_make_call_func(ctx, expr -> item.var, num_args, arguments);
+
+               oberon_assert_token(ctx, RPAREN);
        }
 
        return expr;
 }
 
-#define ISMULOP(x) \
-       ((x) >= STAR && (x) <= AND)
+static void
+oberon_opt_proc_parens(oberon_context_t * ctx, oberon_expr_t * expr)
+{
+       assert(expr -> is_item == 1);
+
+       int num_args = 0;
+       oberon_expr_t * arguments = NULL;
+
+       if(ctx -> token == LPAREN)
+       {
+               oberon_assert_token(ctx, LPAREN);
+
+               if(ISEXPR(ctx -> token))
+               {
+                       oberon_expr_list(ctx, &num_args, &arguments, 0);
+               }
+
+               oberon_assert_token(ctx, RPAREN);
+       }
+
+       /* Вызов происходит даже без скобок */
+       oberon_make_call_proc(ctx, expr -> item.var, num_args, arguments);
+}
 
 static oberon_expr_t *
-oberon_term_expr(oberon_context_t * ctx)
+oberon_factor(oberon_context_t * ctx)
 {
        oberon_expr_t * expr;
 
-       expr = oberon_factor(ctx);
-       while(ISMULOP(ctx -> token))
+       switch(ctx -> token)
        {
-               int token = ctx -> token;
-               oberon_read_token(ctx);
-
-               oberon_expr_t * inter = oberon_factor(ctx);
-               expr = oberon_make_bin_op(ctx, token, expr, inter);
+               case IDENT:
+                       expr = oberon_designator(ctx);
+                       expr = oberon_opt_func_parens(ctx, expr);
+                       break;
+               case INTEGER:
+                       expr = oberon_new_item(MODE_INTEGER, ctx -> int_type, 1);
+                       expr -> item.integer = ctx -> integer;
+                       oberon_assert_token(ctx, INTEGER);
+                       break;
+               case TRUE:
+                       expr = oberon_new_item(MODE_BOOLEAN, ctx -> bool_type, 1);
+                       expr -> item.boolean = 1;
+                       oberon_assert_token(ctx, TRUE);
+                       break;
+               case FALSE:
+                       expr = oberon_new_item(MODE_BOOLEAN, ctx -> bool_type, 1);
+                       expr -> item.boolean = 0;
+                       oberon_assert_token(ctx, FALSE);
+                       break;
+               case LPAREN:
+                       oberon_assert_token(ctx, LPAREN);
+                       expr = oberon_expr(ctx);
+                       oberon_assert_token(ctx, RPAREN);
+                       break;
+               case NOT:
+                       oberon_assert_token(ctx, NOT);
+                       expr = oberon_factor(ctx);
+                       expr = oberon_make_unary_op(ctx, NOT, expr);
+                       break;
+               case NIL:
+                       oberon_assert_token(ctx, NIL);
+                       expr = oberon_new_item(MODE_NIL, ctx -> void_ptr_type, 1);
+                       break;
+               default:
+                       oberon_error(ctx, "invalid expression");
        }
 
        return expr;
 }
 
-#define ISADDOP(x) \
-       ((x) >= PLUS && (x) <= OR)
+/*
+ * oberon_autocast_binary_op автоматически переобразовывеат тип по след. правилам:
+ *   1. Классы обоих типов должны быть одинаковы
+ *   2. В качестве результата должен быть выбран больший тип.
+ *   3. Если размер результат не должен быть меньше чем базовый int
+ */
+
+static void
+oberon_autocast_binary_op(oberon_context_t * ctx, oberon_type_t * a, oberon_type_t * b, oberon_type_t ** result)
+{
+       if((a -> class) != (b -> class))
+       {
+               oberon_error(ctx, "incompatible types");
+       }
+
+       if((a -> size) > (b -> size))
+       {
+               *result = a;
+       }
+       else
+       {
+               *result = b;
+       }
+
+       if(((*result) -> class) == OBERON_TYPE_INTEGER)
+       {
+               if(((*result) -> size) < (ctx -> int_type -> size))
+               {
+                       *result = ctx -> int_type;
+               }
+       }
+
+       /* TODO: cast types */
+}
+
+#define ITMAKESBOOLEAN(x) \
+       (((x) >= EQUAL && (x) <= GEQ) || ((x) == OR) || ((x) == AND))
+
+#define ITUSEONLYINTEGER(x) \
+       ((x) >= LESS && (x) <= GEQ)
+
+#define ITUSEONLYBOOLEAN(x) \
+       (((x) == OR) || ((x) == AND))
+
+static oberon_expr_t *
+oberon_make_bin_op(oberon_context_t * ctx, int token, oberon_expr_t * a, oberon_expr_t * b)
+{
+       oberon_expr_t * expr;
+       oberon_type_t * result;
+
+       if(ITMAKESBOOLEAN(token))
+       {
+               if(ITUSEONLYINTEGER(token))
+               {
+                       if(a -> result -> class != OBERON_TYPE_INTEGER
+                               || b -> result -> class != OBERON_TYPE_INTEGER)
+                       {
+                               oberon_error(ctx, "used only with integer types");
+                       }
+               }
+               else if(ITUSEONLYBOOLEAN(token))
+               {
+                       if(a -> result -> class != OBERON_TYPE_BOOLEAN
+                               || b -> result -> class != OBERON_TYPE_BOOLEAN)
+                       {
+                               oberon_error(ctx, "used only with boolean type");
+                       }
+               }
+
+               result = ctx -> bool_type;
+
+               if(token == EQUAL)
+               {
+                       expr = oberon_new_operator(OP_EQ, result, a, b);
+               }
+               else if(token == NEQ)
+               {
+                       expr = oberon_new_operator(OP_NEQ, result, a, b);
+               }
+               else if(token == LESS)
+               {
+                       expr = oberon_new_operator(OP_LSS, result, a, b);
+               }
+               else if(token == LEQ)
+               {
+                       expr = oberon_new_operator(OP_LEQ, result, a, b);
+               }
+               else if(token == GREAT)
+               {
+                       expr = oberon_new_operator(OP_GRT, result, a, b);
+               }
+               else if(token == GEQ)
+               {
+                       expr = oberon_new_operator(OP_GEQ, result, a, b);
+               }
+               else if(token == OR)
+               {
+                       expr = oberon_new_operator(OP_LOGIC_OR, result, a, b);
+               }
+               else if(token == AND)
+               {
+                       expr = oberon_new_operator(OP_LOGIC_AND, result, a, b);
+               }
+               else
+               {
+                       oberon_error(ctx, "oberon_make_bin_op: bool wat");
+               }
+       }
+       else
+       {
+               oberon_autocast_binary_op(ctx, a -> result, b -> result, &result);
+
+               if(token == PLUS)
+               {
+                       expr = oberon_new_operator(OP_ADD, result, a, b);
+               }
+               else if(token == MINUS)
+               {
+                       expr = oberon_new_operator(OP_SUB, result, a, b);
+               }
+               else if(token == STAR)
+               {
+                       expr = oberon_new_operator(OP_MUL, result, a, b);
+               }
+               else if(token == SLASH)
+               {
+                       expr = oberon_new_operator(OP_DIV, result, a, b);
+               }
+               else if(token == DIV)
+               {
+                       expr = oberon_new_operator(OP_DIV, result, a, b);
+               }
+               else if(token == MOD)
+               {
+                       expr = oberon_new_operator(OP_MOD, result, a, b);
+               }
+               else
+               {
+                       oberon_error(ctx, "oberon_make_bin_op: bin wat");
+               }
+       }
+
+       return expr;
+}
+
+#define ISMULOP(x) \
+       ((x) >= STAR && (x) <= AND)
+
+static oberon_expr_t *
+oberon_term_expr(oberon_context_t * ctx)
+{
+       oberon_expr_t * expr;
+
+       expr = oberon_factor(ctx);
+       while(ISMULOP(ctx -> token))
+       {
+               int token = ctx -> token;
+               oberon_read_token(ctx);
+
+               oberon_expr_t * inter = oberon_factor(ctx);
+               expr = oberon_make_bin_op(ctx, token, expr, inter);
+       }
+
+       return expr;
+}
+
+#define ISADDOP(x) \
+       ((x) >= PLUS && (x) <= OR)
+
+static oberon_expr_t *
+oberon_simple_expr(oberon_context_t * ctx)
+{
+       oberon_expr_t * expr;
+
+       int minus = 0;
+       if(ctx -> token == PLUS)
+       {
+               minus = 0;
+               oberon_assert_token(ctx, PLUS);
+       }
+       else if(ctx -> token == MINUS)
+       {
+               minus = 1;
+               oberon_assert_token(ctx, MINUS);
+       }
+
+       expr = oberon_term_expr(ctx);
+       while(ISADDOP(ctx -> token))
+       {
+               int token = ctx -> token;
+               oberon_read_token(ctx);
+
+               oberon_expr_t * inter = oberon_term_expr(ctx);
+               expr = oberon_make_bin_op(ctx, token, expr, inter);
+       }
+
+       if(minus)
+       {
+               expr = oberon_make_unary_op(ctx, MINUS, expr);
+       }
+
+       return expr;
+}
+
+#define ISRELATION(x) \
+       ((x) >= EQUAL && (x) <= GEQ)
+
+static oberon_expr_t *
+oberon_expr(oberon_context_t * ctx)
+{
+       oberon_expr_t * expr;
+
+       expr = oberon_simple_expr(ctx);
+       while(ISRELATION(ctx -> token))
+       {
+               int token = ctx -> token;
+               oberon_read_token(ctx);
+
+               oberon_expr_t * inter = oberon_simple_expr(ctx);
+               expr = oberon_make_bin_op(ctx, token, expr, inter);
+       }
+
+       return expr;
+}
+
+static oberon_item_t *
+oberon_const_expr(oberon_context_t * ctx)
+{
+       oberon_expr_t * expr;
+       expr = oberon_expr(ctx);
+
+       if(expr -> is_item == 0)
+       {
+               oberon_error(ctx, "const expression are required");
+       }
+
+       return (oberon_item_t *) expr;
+}
+
+// =======================================================================
+//   PARSER
+// =======================================================================
+
+static void oberon_decl_seq(oberon_context_t * ctx);
+static void oberon_statement_seq(oberon_context_t * ctx);
+static void oberon_initialize_decl(oberon_context_t * ctx);
+
+static void
+oberon_expect_token(oberon_context_t * ctx, int token)
+{
+       if(ctx -> token != token)
+       {
+               oberon_error(ctx, "unexpected token %i (%i)", ctx -> token, token);
+       }
+}
+
+static void
+oberon_assert_token(oberon_context_t * ctx, int token)
+{
+       oberon_expect_token(ctx, token);
+       oberon_read_token(ctx);
+}
+
+static char *
+oberon_assert_ident(oberon_context_t * ctx)
+{
+       oberon_expect_token(ctx, IDENT);
+       char * ident = ctx -> string;
+       oberon_read_token(ctx);
+       return ident;
+}
+
+static void
+oberon_def(oberon_context_t * ctx, int * export, int * read_only)
+{
+       switch(ctx -> token)
+       {
+               case STAR:
+                       oberon_assert_token(ctx, STAR);
+                       *export = 1;
+                       *read_only = 0;
+                       break;
+               case MINUS:
+                       oberon_assert_token(ctx, MINUS);
+                       *export = 1;
+                       *read_only = 1;
+                       break;
+               default:
+                       *export = 0;
+                       *read_only = 0;
+                       break;
+       }
+}
+
+static oberon_object_t *
+oberon_ident_def(oberon_context_t * ctx, int class)
+{
+       char * name;
+       int export;
+       int read_only;
+       oberon_object_t * x;
+
+       name = oberon_assert_ident(ctx);
+       oberon_def(ctx, &export, &read_only);
+
+       x = oberon_define_object(ctx -> decl, name, class, export, read_only);
+       return x;
+}
+
+static void
+oberon_ident_list(oberon_context_t * ctx, int class, int * num, oberon_object_t ** list)
+{
+       *num = 1;
+       *list = oberon_ident_def(ctx, class);
+       while(ctx -> token == COMMA)
+       {
+               oberon_assert_token(ctx, COMMA);
+               oberon_ident_def(ctx, class);
+               *num += 1;
+       }
+}
+
+static void
+oberon_var_decl(oberon_context_t * ctx)
+{
+       int num;
+       oberon_object_t * list;
+       oberon_type_t * type;
+       type = oberon_new_type_ptr(OBERON_TYPE_VOID);
+
+       oberon_ident_list(ctx, OBERON_CLASS_VAR, &num, &list);
+       oberon_assert_token(ctx, COLON);
+       oberon_type(ctx, &type);
+
+       oberon_object_t * var = list;
+       for(int i = 0; i < num; i++)
+       {
+               var -> type = type;
+               var = var -> next;
+       }
+}
+
+static oberon_object_t *
+oberon_fp_section(oberon_context_t * ctx, int * num_decl)
+{
+       int class = OBERON_CLASS_PARAM;
+       if(ctx -> token == VAR)
+       {
+               oberon_read_token(ctx);
+               class = OBERON_CLASS_VAR_PARAM;
+       }
+
+       int num;
+       oberon_object_t * list;
+       oberon_ident_list(ctx, class, &num, &list);
+
+       oberon_assert_token(ctx, COLON);
+
+       oberon_type_t * type;
+       type = oberon_new_type_ptr(OBERON_TYPE_VOID);
+       oberon_type(ctx, &type);
+
+       oberon_object_t * param = list;
+       for(int i = 0; i < num; i++)
+       {
+               param -> type = type;
+               param = param -> next;
+       }
+
+       *num_decl += num;
+       return list;
+}
+
+#define ISFPSECTION \
+       ((ctx -> token == VAR) || (ctx -> token == IDENT))
+
+static void
+oberon_formal_pars(oberon_context_t * ctx, oberon_type_t * signature)
+{
+       oberon_assert_token(ctx, LPAREN);
+
+       if(ISFPSECTION)
+       {
+               signature -> decl = oberon_fp_section(ctx, &signature -> num_decl);
+               while(ctx -> token == SEMICOLON)
+               {
+                       oberon_assert_token(ctx, SEMICOLON);
+                       oberon_fp_section(ctx, &signature -> num_decl);
+               }
+       }
+
+       oberon_assert_token(ctx, RPAREN);
+
+       if(ctx -> token == COLON)
+       {
+               oberon_assert_token(ctx, COLON);
+
+               oberon_object_t * typeobj;
+               typeobj = oberon_qualident(ctx, NULL, 1);
+               if(typeobj -> class != OBERON_CLASS_TYPE)
+               {
+                       oberon_error(ctx, "function result is not type");
+               }
+               signature -> base = typeobj -> type;
+       }
+}
+
+static void
+oberon_opt_formal_pars(oberon_context_t * ctx, oberon_type_t ** type)
+{
+       oberon_type_t * signature;
+       signature = *type;
+       signature -> class = OBERON_TYPE_PROCEDURE;
+       signature -> num_decl = 0;
+       signature -> base = ctx -> void_type;
+       signature -> decl = NULL;
+
+       if(ctx -> token == LPAREN)
+       {
+               oberon_formal_pars(ctx, signature);
+       }
+}
+
+static void
+oberon_compare_signatures(oberon_context_t * ctx, oberon_type_t * a, oberon_type_t * b)
+{
+       if(a -> num_decl != b -> num_decl)
+       {
+               oberon_error(ctx, "number parameters not matched");
+       }
+
+       int num_param = a -> num_decl;
+       oberon_object_t * param_a = a -> decl;
+       oberon_object_t * param_b = b -> decl;
+       for(int i = 0; i < num_param; i++)
+       {
+               if(strcmp(param_a -> name, param_b -> name) != 0)
+               {
+                       oberon_error(ctx, "param %i name not matched", i + 1);
+               }
+
+               if(param_a -> type != param_b -> type)
+               {
+                       oberon_error(ctx, "param %i type not matched", i + 1);
+               }
+
+               param_a = param_a -> next;
+               param_b = param_b -> next;
+       }
+}
+
+static void
+oberon_make_return(oberon_context_t * ctx, oberon_expr_t * expr)
+{
+       oberon_object_t * proc = ctx -> decl -> parent;
+       oberon_type_t * result_type = proc -> type -> base;
+
+       if(result_type -> class == OBERON_TYPE_VOID)
+       {
+               if(expr != NULL)
+               {
+                       oberon_error(ctx, "procedure has no result type");
+               }
+       }
+       else
+       {
+               if(expr == NULL)
+               {
+                       oberon_error(ctx, "procedure requires expression on result");
+               }
+
+               oberon_autocast_to(ctx, expr, result_type);
+       }
+
+       proc -> has_return = 1;
+
+       oberon_generate_return(ctx, expr);
+}
+
+static void
+oberon_proc_decl_body(oberon_context_t * ctx, oberon_object_t * proc)
+{
+       oberon_assert_token(ctx, SEMICOLON);
+
+       ctx -> decl = proc -> scope;
+
+       oberon_decl_seq(ctx);
+
+       oberon_generate_begin_proc(ctx, proc);
+
+       if(ctx -> token == BEGIN)
+       {
+               oberon_assert_token(ctx, BEGIN);
+               oberon_statement_seq(ctx);
+       }
+
+       oberon_assert_token(ctx, END);
+       char * name = oberon_assert_ident(ctx);
+       if(strcmp(name, proc -> name) != 0)
+       {
+               oberon_error(ctx, "procedure name not matched");
+       }
+
+       if(proc -> type -> base -> class == OBERON_TYPE_VOID
+               && proc -> has_return == 0)
+       {
+               oberon_make_return(ctx, NULL);
+       }
+
+       if(proc -> has_return == 0)
+       {
+               oberon_error(ctx, "procedure requires return");
+       }
+
+       oberon_generate_end_proc(ctx);
+       oberon_close_scope(ctx -> decl);
+}
+
+static void
+oberon_proc_decl(oberon_context_t * ctx)
+{
+       oberon_assert_token(ctx, PROCEDURE);
+
+       int forward = 0;
+       if(ctx -> token == UPARROW)
+       {
+               oberon_assert_token(ctx, UPARROW);
+               forward = 1;
+       }
+
+       char * name;
+       int export;
+       int read_only;
+       name = oberon_assert_ident(ctx);
+       oberon_def(ctx, &export, &read_only);
+
+       oberon_scope_t * proc_scope;
+       proc_scope = oberon_open_scope(ctx);
+       ctx -> decl -> local = 1;
+
+       oberon_type_t * signature;
+       signature = oberon_new_type_ptr(OBERON_TYPE_VOID);
+       oberon_opt_formal_pars(ctx, &signature);        
+
+       oberon_initialize_decl(ctx);
+       oberon_generator_init_type(ctx, signature);
+       oberon_close_scope(ctx -> decl);
+
+       oberon_object_t * proc;
+       proc = oberon_find_object(ctx -> decl, name, 0);
+       if(proc != NULL)
+       {
+               if(proc -> class != OBERON_CLASS_PROC)
+               {
+                       oberon_error(ctx, "mult definition");
+               }
+
+               if(forward == 0)
+               {
+                       if(proc -> linked)
+                       {
+                               oberon_error(ctx, "mult procedure definition");
+                       }
+               }
+
+               if(proc -> export != export || proc -> read_only != read_only)
+               {
+                       oberon_error(ctx, "export type not matched");
+               }
+
+               oberon_compare_signatures(ctx, proc -> type, signature);
+       }
+       else
+       {
+               proc = oberon_define_object(ctx -> decl, name, OBERON_CLASS_PROC, export, read_only);
+               proc -> type = signature;
+               proc -> scope = proc_scope;
+               oberon_generator_init_proc(ctx, proc);
+       }
+
+       proc -> scope -> parent = proc;
+
+       if(forward == 0)
+       {
+               proc -> linked = 1;
+               oberon_proc_decl_body(ctx, proc);
+       }
+}
+
+static void
+oberon_const_decl(oberon_context_t * ctx)
+{
+       oberon_item_t * value;
+       oberon_object_t * constant;
+
+       constant = oberon_ident_def(ctx, OBERON_CLASS_CONST);
+       oberon_assert_token(ctx, EQUAL);
+       value = oberon_const_expr(ctx);
+       constant -> value = value;
+}
+
+static void
+oberon_make_array_type(oberon_context_t * ctx, oberon_expr_t * size, oberon_type_t * base, oberon_type_t ** type)
+{
+       if(size -> is_item == 0)
+       {
+               oberon_error(ctx, "requires constant");
+       }
+
+       if(size -> item.mode != MODE_INTEGER)
+       {
+               oberon_error(ctx, "requires integer constant");
+       }
+
+       oberon_type_t * arr;
+       arr = *type;
+       arr -> class = OBERON_TYPE_ARRAY;
+       arr -> size = size -> item.integer;
+       arr -> base = base;
+}
+
+static void
+oberon_field_list(oberon_context_t * ctx, oberon_type_t * rec)
+{
+       if(ctx -> token == IDENT)
+       {
+               int num;
+               oberon_object_t * list;
+               oberon_type_t * type;
+               type = oberon_new_type_ptr(OBERON_TYPE_VOID);
+
+               oberon_ident_list(ctx, OBERON_CLASS_FIELD, &num, &list);
+               oberon_assert_token(ctx, COLON);
+               oberon_type(ctx, &type);
+
+               oberon_object_t * field = list;
+               for(int i = 0; i < num; i++)
+               {
+                       field -> type = type;
+                       field = field -> next;
+               }
+
+               rec -> num_decl += num;
+       }
+}
+
+static void
+oberon_qualident_type(oberon_context_t * ctx, oberon_type_t ** type)
+{
+       char * name;
+       oberon_object_t * to;
+
+       to = oberon_qualident(ctx, &name, 0);
+
+       //name = oberon_assert_ident(ctx);
+       //to = oberon_find_object(ctx -> decl, name, 0);
+
+       if(to != NULL)
+       {
+               if(to -> class != OBERON_CLASS_TYPE)
+               {
+                       oberon_error(ctx, "not a type");
+               }
+       }
+       else
+       {
+               to = oberon_define_object(ctx -> decl, name, OBERON_CLASS_TYPE, 0, 0);
+               to -> type = oberon_new_type_ptr(OBERON_TYPE_VOID);
+       }
+
+       *type = to -> type;
+}
+
+static void oberon_opt_formal_pars(oberon_context_t * ctx, oberon_type_t ** type);
+
+/*
+ * Правило граматики "type". Указатель type должен указывать на существующий объект!
+ */
+
+static void
+oberon_make_multiarray(oberon_context_t * ctx, oberon_expr_t * sizes, oberon_type_t * base, oberon_type_t ** type)
+{
+       if(sizes == NULL)
+       {
+               *type = base;
+               return;
+       }
+
+       oberon_type_t * dim;
+       dim = oberon_new_type_ptr(OBERON_TYPE_VOID);
+
+       oberon_make_multiarray(ctx, sizes -> next, base, &dim);
+
+       oberon_make_array_type(ctx, sizes, dim, type);
+}
+
+static void
+oberon_type(oberon_context_t * ctx, oberon_type_t ** type)
+{
+       if(ctx -> token == IDENT)
+       {
+               oberon_qualident_type(ctx, type);
+       }
+       else if(ctx -> token == ARRAY)
+       {
+               oberon_assert_token(ctx, ARRAY);
+
+               int num_sizes = 0;
+               oberon_expr_t * sizes;
+               oberon_expr_list(ctx, &num_sizes, &sizes, 1);
+
+               oberon_assert_token(ctx, OF);
+
+               oberon_type_t * base;
+               base = oberon_new_type_ptr(OBERON_TYPE_VOID);
+               oberon_type(ctx, &base);
+
+               oberon_make_multiarray(ctx, sizes, base, type);
+       }
+       else if(ctx -> token == RECORD)
+       {
+               oberon_type_t * rec;
+               rec = *type;
+               rec -> class = OBERON_TYPE_RECORD;
+
+               oberon_scope_t * record_scope;
+               record_scope = oberon_open_scope(ctx);
+               // TODO parent object
+               //record_scope -> parent = NULL;
+               record_scope -> local = 1;
+
+               oberon_assert_token(ctx, RECORD);
+               oberon_field_list(ctx, rec);
+               while(ctx -> token == SEMICOLON)
+               {
+                       oberon_assert_token(ctx, SEMICOLON);
+                       oberon_field_list(ctx, rec);
+               }
+               oberon_assert_token(ctx, END);
+
+               rec -> decl = record_scope -> list -> next;
+               oberon_close_scope(record_scope);
+
+               *type = rec;
+       }
+       else if(ctx -> token == POINTER)
+       {
+               oberon_assert_token(ctx, POINTER);
+               oberon_assert_token(ctx, TO);
+
+               oberon_type_t * base;
+               base = oberon_new_type_ptr(OBERON_TYPE_VOID);
+               oberon_type(ctx, &base);
+
+               oberon_type_t * ptr;
+               ptr = *type;
+               ptr -> class = OBERON_TYPE_POINTER;
+               ptr -> base = base;
+       }
+       else if(ctx -> token == PROCEDURE)
+       {
+               oberon_open_scope(ctx);
+               oberon_assert_token(ctx, PROCEDURE);
+               oberon_opt_formal_pars(ctx, type);
+               oberon_close_scope(ctx -> decl);
+       }
+       else
+       {
+               oberon_error(ctx, "invalid type declaration");
+       }
+}
+
+static void
+oberon_type_decl(oberon_context_t * ctx)
+{
+       char * name;
+       oberon_object_t * newtype;
+       oberon_type_t * type;
+       int export;
+       int read_only;
+
+       name = oberon_assert_ident(ctx);
+       oberon_def(ctx, &export, &read_only);
+
+       newtype = oberon_find_object(ctx -> decl, name, 0);
+       if(newtype == NULL)
+       {
+               newtype = oberon_define_object(ctx -> decl, name, OBERON_CLASS_TYPE, export, read_only);
+               newtype -> type = oberon_new_type_ptr(OBERON_TYPE_VOID);
+               assert(newtype -> type);
+       }
+       else
+       {
+               if(newtype -> class != OBERON_CLASS_TYPE)
+               {
+                       oberon_error(ctx, "mult definition");
+               }
+
+               if(newtype -> linked)
+               {
+                       oberon_error(ctx, "mult definition - already linked");
+               }
+
+               newtype -> export = export;
+               newtype -> read_only = read_only;
+       }
+
+       oberon_assert_token(ctx, EQUAL);
+
+       type = newtype -> type;
+       oberon_type(ctx, &type);
+
+       if(type -> class == OBERON_TYPE_VOID)
+       {
+               oberon_error(ctx, "recursive alias declaration");
+       }
+
+       newtype -> type = type;
+       newtype -> linked = 1;
+}
+
+static void oberon_prevent_recursive_object(oberon_context_t * ctx, oberon_object_t * x);
+static void oberon_prevent_recursive_type(oberon_context_t * ctx, oberon_type_t * type);
+
+static void
+oberon_prevent_recursive_pointer(oberon_context_t * ctx, oberon_type_t * type)
+{
+       if(type -> class != OBERON_TYPE_POINTER
+               && type -> class != OBERON_TYPE_ARRAY)
+       {
+               return;
+       }
+
+       if(type -> recursive)
+       {
+               oberon_error(ctx, "recursive pointer declaration");
+       }
+
+       if(type -> base -> class == OBERON_TYPE_POINTER)
+       {
+               oberon_error(ctx, "attempt to make pointer to pointer");
+       }
+
+       type -> recursive = 1;
+
+       oberon_prevent_recursive_pointer(ctx, type -> base);
+
+       type -> recursive = 0;
+}
 
-static oberon_expr_t *
-oberon_simple_expr(oberon_context_t * ctx)
+static void
+oberon_prevent_recursive_record(oberon_context_t * ctx, oberon_type_t * type)
 {
-       oberon_expr_t * expr;
+       if(type -> class != OBERON_TYPE_RECORD)
+       {
+               return;
+       }
 
-       int minus = 0;
-       if(ctx -> token == PLUS)
+       if(type -> recursive)
        {
-               minus = 0;
-               oberon_assert_token(ctx, PLUS);
+               oberon_error(ctx, "recursive record declaration");
        }
-       else if(ctx -> token == MINUS)
+
+       type -> recursive = 1;
+
+       int num_fields = type -> num_decl;
+       oberon_object_t * field = type -> decl;
+       for(int i = 0; i < num_fields; i++)
        {
-               minus = 1;
-               oberon_assert_token(ctx, MINUS);
+               oberon_prevent_recursive_object(ctx, field);
+               field = field -> next;
        }
 
-       expr = oberon_term_expr(ctx);
-       while(ISADDOP(ctx -> token))
+       type -> recursive = 0;  
+}
+static void
+oberon_prevent_recursive_procedure(oberon_context_t * ctx, oberon_type_t * type)
+{
+       if(type -> class != OBERON_TYPE_PROCEDURE)
        {
-               int token = ctx -> token;
-               oberon_read_token(ctx);
+               return;
+       }
 
-               oberon_expr_t * inter = oberon_term_expr(ctx);
-               expr = oberon_make_bin_op(ctx, token, expr, inter);
+       if(type -> recursive)
+       {
+               oberon_error(ctx, "recursive procedure declaration");
        }
 
-       if(minus)
+       type -> recursive = 1;
+
+       int num_fields = type -> num_decl;
+       oberon_object_t * field = type -> decl;
+       for(int i = 0; i < num_fields; i++)
        {
-               expr = oberon_make_unary_op(ctx, MINUS, expr);
+               oberon_prevent_recursive_object(ctx, field);
+               field = field -> next;
        }
 
-       return expr;
+       type -> recursive = 0;  
 }
 
-#define ISRELATION(x) \
-       ((x) >= EQUAL && (x) <= GEQ)
-
-static oberon_expr_t *
-oberon_expr(oberon_context_t * ctx)
+static void
+oberon_prevent_recursive_array(oberon_context_t * ctx, oberon_type_t * type)
 {
-       oberon_expr_t * expr;
-
-       expr = oberon_simple_expr(ctx);
-       while(ISRELATION(ctx -> token))
+       if(type -> class != OBERON_TYPE_ARRAY)
        {
-               int token = ctx -> token;
-               oberon_read_token(ctx);
+               return;
+       }
 
-               oberon_expr_t * inter = oberon_simple_expr(ctx);
-               expr = oberon_make_bin_op(ctx, token, expr, inter);
+       if(type -> recursive)
+       {
+               oberon_error(ctx, "recursive array declaration");
        }
 
-       return expr;
-}
+       type -> recursive = 1;
 
-// =======================================================================
-//   PARSER
-// =======================================================================
+       oberon_prevent_recursive_type(ctx, type -> base);
 
-static void oberon_statement_seq(oberon_context_t * ctx);
+       type -> recursive = 0;
+}
 
 static void
-oberon_expect_token(oberon_context_t * ctx, int token)
+oberon_prevent_recursive_type(oberon_context_t * ctx, oberon_type_t * type)
 {
-       if(ctx -> token != token)
+       if(type -> class == OBERON_TYPE_POINTER)
        {
-               oberon_error(ctx, "unexpected token %i (%i)", ctx -> token, token);
+               oberon_prevent_recursive_pointer(ctx, type);
+       }
+       else if(type -> class == OBERON_TYPE_RECORD)
+       {
+               oberon_prevent_recursive_record(ctx, type);
+       }
+       else if(type -> class == OBERON_TYPE_ARRAY)
+       {
+               oberon_prevent_recursive_array(ctx, type);
+       }
+       else if(type -> class == OBERON_TYPE_PROCEDURE)
+       {
+               oberon_prevent_recursive_procedure(ctx, type);
        }
 }
 
 static void
-oberon_assert_token(oberon_context_t * ctx, int token)
+oberon_prevent_recursive_object(oberon_context_t * ctx, oberon_object_t * x)
 {
-       oberon_expect_token(ctx, token);
-       oberon_read_token(ctx);
+       switch(x -> class)
+       {
+               case OBERON_CLASS_VAR:
+               case OBERON_CLASS_TYPE:
+               case OBERON_CLASS_PARAM:
+               case OBERON_CLASS_VAR_PARAM:
+               case OBERON_CLASS_FIELD:
+                       oberon_prevent_recursive_type(ctx, x -> type);
+                       break;
+               case OBERON_CLASS_CONST:
+               case OBERON_CLASS_PROC:
+               case OBERON_CLASS_MODULE:
+                       break;
+               default:
+                       oberon_error(ctx, "oberon_prevent_recursive_object: wat");
+                       break;
+       }
 }
 
-static char *
-oberon_assert_ident(oberon_context_t * ctx)
+static void
+oberon_prevent_recursive_decl(oberon_context_t * ctx)
 {
-       oberon_expect_token(ctx, IDENT);
-       char * ident = ctx -> string;
-       oberon_read_token(ctx);
-       return ident;
+       oberon_object_t * x = ctx -> decl -> list -> next;
+
+       while(x)
+       {
+               oberon_prevent_recursive_object(ctx, x);
+               x = x -> next;
+       }
 }
 
-static oberon_type_t *
-oberon_type(oberon_context_t * ctx)
+static void oberon_initialize_object(oberon_context_t * ctx, oberon_object_t * x);
+static void oberon_initialize_type(oberon_context_t * ctx, oberon_type_t * type);
+
+static void
+oberon_initialize_record_fields(oberon_context_t * ctx, oberon_type_t * type)
 {
-       char * name = oberon_assert_ident(ctx);
-       oberon_type_t * type = oberon_find_type(ctx, name);
+       if(type -> class != OBERON_TYPE_RECORD)
+       {
+               return;
+       }
 
-       if(type == NULL)
+       int num_fields = type -> num_decl;
+       oberon_object_t * field = type -> decl;
+       for(int i = 0; i < num_fields; i++)
        {
-               oberon_error(ctx, "undefined type");
+               if(field -> type -> class == OBERON_TYPE_POINTER)
+               {
+                       oberon_initialize_type(ctx, field -> type);
+               }
+
+               oberon_initialize_object(ctx, field);
+               field = field -> next;
        }
 
-       return type;
+       oberon_generator_init_record(ctx, type);
 }
 
 static void
-oberon_var_decl(oberon_context_t * ctx)
+oberon_initialize_type(oberon_context_t * ctx, oberon_type_t * type)
 {
-       char * name = oberon_assert_ident(ctx);
-       oberon_assert_token(ctx, COLON);
-       oberon_type_t * type = oberon_type(ctx);
-       oberon_define_var(ctx, name, type);
+       if(type -> class == OBERON_TYPE_VOID)
+       {
+               oberon_error(ctx, "undeclarated type");
+       }
+
+       if(type -> initialized)
+       {
+               return;
+       }
+
+       type -> initialized = 1;
+
+       if(type -> class == OBERON_TYPE_POINTER)
+       {
+               oberon_initialize_type(ctx, type -> base);
+               oberon_generator_init_type(ctx, type);
+       }
+       else if(type -> class == OBERON_TYPE_ARRAY)
+       {
+               oberon_initialize_type(ctx, type -> base);              
+               oberon_generator_init_type(ctx, type);
+       }
+       else if(type -> class == OBERON_TYPE_RECORD)
+       {
+               oberon_generator_init_type(ctx, type);
+               oberon_initialize_record_fields(ctx, type);
+       }
+       else if(type -> class == OBERON_TYPE_PROCEDURE)
+       {
+               int num_fields = type -> num_decl;
+               oberon_object_t * field = type -> decl;
+               for(int i = 0; i < num_fields; i++)
+               {
+                       oberon_initialize_object(ctx, field);
+                       field = field -> next;
+               }               
+
+               oberon_generator_init_type(ctx, type);
+       }
+       else
+       {
+               oberon_generator_init_type(ctx, type);
+       }
 }
 
 static void
-oberon_make_procedure_begin(oberon_context_t * ctx, char * name)
+oberon_initialize_object(oberon_context_t * ctx, oberon_object_t * x)
 {
-       
+       if(x -> initialized)
+       {
+               return;
+       }
+
+       x -> initialized = 1;
+
+       switch(x -> class)
+       {
+               case OBERON_CLASS_TYPE:
+                       oberon_initialize_type(ctx, x -> type);
+                       break;
+               case OBERON_CLASS_VAR:
+               case OBERON_CLASS_PARAM:
+               case OBERON_CLASS_VAR_PARAM:
+               case OBERON_CLASS_FIELD:
+                       oberon_initialize_type(ctx, x -> type);
+                       oberon_generator_init_var(ctx, x);
+                       break;
+               case OBERON_CLASS_CONST:
+               case OBERON_CLASS_PROC:
+               case OBERON_CLASS_MODULE:
+                       break;
+               default:
+                       oberon_error(ctx, "oberon_initialize_object: wat");
+                       break;
+       }
 }
 
 static void
-oberon_make_procedure_end(oberon_context_t * ctx)
+oberon_initialize_decl(oberon_context_t * ctx)
 {
+       oberon_object_t * x = ctx -> decl -> list;
 
+       while(x -> next)
+       {
+               oberon_initialize_object(ctx, x -> next);
+               x = x -> next;
+       }       
 }
 
 static void
-oberon_proc_decl(oberon_context_t * ctx)
+oberon_prevent_undeclarated_procedures(oberon_context_t * ctx)
 {
-       oberon_assert_token(ctx, PROCEDURE);
-
-       char * name;
-       name = oberon_assert_ident(ctx);
+       oberon_object_t * x = ctx -> decl -> list;
 
-       oberon_assert_token(ctx, SEMICOLON);
+       while(x -> next)
+       {
+               if(x -> next -> class == OBERON_CLASS_PROC)
+               {
+                       if(x -> next -> linked == 0)
+                       {
+                               oberon_error(ctx, "unresolved forward declaration");
+                       }
+               }
+               x = x -> next;
+       }       
+}
 
-       oberon_make_procedure_begin(ctx, name);
-       if(ctx -> token == BEGIN)
+static void
+oberon_decl_seq(oberon_context_t * ctx)
+{
+       if(ctx -> token == CONST)
        {
-               oberon_assert_token(ctx, BEGIN);
-               oberon_statement_seq(ctx);
+               oberon_assert_token(ctx, CONST);
+               while(ctx -> token == IDENT)
+               {
+                       oberon_const_decl(ctx);
+                       oberon_assert_token(ctx, SEMICOLON);
+               }
        }
-       oberon_make_procedure_end(ctx);
-
-       oberon_assert_token(ctx, END);
-       char * name2 = oberon_assert_ident(ctx);
 
-       if(strcmp(name2, name) != 0)
+       if(ctx -> token == TYPE)
        {
-               oberon_error(ctx, "procedure name not matched");
+               oberon_assert_token(ctx, TYPE);
+               while(ctx -> token == IDENT)
+               {
+                       oberon_type_decl(ctx);
+                       oberon_assert_token(ctx, SEMICOLON);
+               }
        }
-}
 
-static void
-oberon_decl_seq(oberon_context_t * ctx)
-{
        if(ctx -> token == VAR)
        {
                oberon_assert_token(ctx, VAR);
@@ -792,29 +2280,27 @@ oberon_decl_seq(oberon_context_t * ctx)
                }
        }
 
-       if(ctx -> token == PROCEDURE)
+       oberon_prevent_recursive_decl(ctx);
+       oberon_initialize_decl(ctx);
+
+       while(ctx -> token == PROCEDURE)
        {
                oberon_proc_decl(ctx);
                oberon_assert_token(ctx, SEMICOLON);
        }
+
+       oberon_prevent_undeclarated_procedures(ctx);
 }
 
 static void
 oberon_assign(oberon_context_t * ctx, oberon_expr_t * src, oberon_expr_t * dst)
 {
-       if(src -> result -> class != dst -> result -> class)
+       if(dst -> read_only)
        {
-               oberon_error(ctx, "incompatible assignment types");
-       }
-
-       if(dst -> result -> class == OBERON_TYPE_INTEGER)
-       {
-               if((dst -> result -> size) < (src -> result -> size))
-               {
-                       oberon_error(ctx, "incompatible assignment type size");
-               }
+               oberon_error(ctx, "read-only destination");
        }
 
+       oberon_autocast_to(ctx, src, dst -> result);
        oberon_generate_assign(ctx, src, dst);
 }
 
@@ -826,10 +2312,31 @@ oberon_statement(oberon_context_t * ctx)
 
        if(ctx -> token == IDENT)
        {
-               item1 = oberon_expr(ctx);
-               oberon_assert_token(ctx, ASSIGN);
-               item2 = oberon_expr(ctx);
-               oberon_assign(ctx, item2, item1);
+               item1 = oberon_designator(ctx);
+               if(ctx -> token == ASSIGN)
+               {
+                       oberon_assert_token(ctx, ASSIGN);
+                       item2 = oberon_expr(ctx);
+                       oberon_assign(ctx, item2, item1);
+               }
+               else
+               {
+                       oberon_opt_proc_parens(ctx, item1);
+               }
+       }
+       else if(ctx -> token == RETURN)
+       {
+               oberon_assert_token(ctx, RETURN);
+               if(ISEXPR(ctx -> token))
+               {
+                       oberon_expr_t * expr;
+                       expr = oberon_expr(ctx);
+                       oberon_make_return(ctx, expr);
+               }
+               else
+               {
+                       oberon_make_return(ctx, NULL);
+               }
        }
 }
 
@@ -844,10 +2351,74 @@ oberon_statement_seq(oberon_context_t * ctx)
        }
 }
 
+static void
+oberon_import_module(oberon_context_t * ctx, char * alias, char * name)
+{
+       oberon_module_t * m = ctx -> module_list;
+       while(m && strcmp(m -> name, name) != 0)
+       {
+               m = m -> next;
+       }
+
+       if(m == NULL)
+       {
+               const char * code;
+               code = ctx -> import_module(name);
+               if(code == NULL)
+               {
+                       oberon_error(ctx, "no such module");
+               }
+
+               m = oberon_compile_module(ctx, code);
+               assert(m);
+       }
+
+       if(m -> ready == 0)
+       {
+               oberon_error(ctx, "cyclic module import");
+       }
+
+       oberon_object_t * ident;
+       ident = oberon_define_object(ctx -> decl, alias, OBERON_CLASS_MODULE, 0, 0);
+       ident -> module = m;
+}
+
+static void
+oberon_import_decl(oberon_context_t * ctx)
+{
+       char * alias;
+       char * name;
+
+       alias = name = oberon_assert_ident(ctx);
+       if(ctx -> token == ASSIGN)
+       {
+               oberon_assert_token(ctx, ASSIGN);
+               name = oberon_assert_ident(ctx);
+       }
+
+       oberon_import_module(ctx, alias, name);
+}
+
+static void
+oberon_import_list(oberon_context_t * ctx)
+{
+       oberon_assert_token(ctx, IMPORT);
+
+       oberon_import_decl(ctx);
+       while(ctx -> token == COMMA)
+       {
+               oberon_assert_token(ctx, COMMA);
+               oberon_import_decl(ctx);
+       }
+
+       oberon_assert_token(ctx, SEMICOLON);
+}
+
 static void
 oberon_parse_module(oberon_context_t * ctx)
 {
-       char *name1, *name2;
+       char * name1;
+       char * name2;
        oberon_read_token(ctx);
 
        oberon_assert_token(ctx, MODULE);
@@ -855,15 +2426,20 @@ oberon_parse_module(oberon_context_t * ctx)
        oberon_assert_token(ctx, SEMICOLON);
        ctx -> mod -> name = name1;
 
+       if(ctx -> token == IMPORT)
+       {
+               oberon_import_list(ctx);
+       }
+
        oberon_decl_seq(ctx);
 
+       oberon_generate_begin_module(ctx);
        if(ctx -> token == BEGIN)
        {
                oberon_assert_token(ctx, BEGIN);
-               oberon_generate_begin_module(ctx);
                oberon_statement_seq(ctx);
-               oberon_generate_end_module(ctx);
        }
+       oberon_generate_end_module(ctx);
 
        oberon_assert_token(ctx, END);
        name2 = oberon_assert_ident(ctx);
@@ -879,59 +2455,79 @@ oberon_parse_module(oberon_context_t * ctx)
 //   LIBRARY
 // =======================================================================
 
-static oberon_type_t *
-oberon_register_global_type_ret(oberon_context_t * ctx, oberon_type_t * type)
+static void
+register_default_types(oberon_context_t * ctx)
 {
-       oberon_type_t * x = ctx -> types;
-       while(x -> next && strcmp(x -> next -> name, type -> name) != 0)
-       {
-               x = x -> next;
-       }
+       ctx -> void_type = oberon_new_type_ptr(OBERON_TYPE_VOID);
+       oberon_generator_init_type(ctx, ctx -> void_type);
 
-       if(x -> next)
-       {
-               oberon_error(ctx, "already defined");
-       }
+       ctx -> void_ptr_type = oberon_new_type_ptr(OBERON_TYPE_POINTER);
+       ctx -> void_ptr_type -> base = ctx -> void_type;
+       oberon_generator_init_type(ctx, ctx -> void_ptr_type);
 
-       // TODO: copy type name (not a pointer)
-       oberon_type_t * newtype = malloc(sizeof *newtype);
-       memcpy(newtype, type, sizeof *newtype);
-       newtype -> next = NULL;
-       oberon_generator_init_type(ctx, newtype);
+       ctx -> int_type = oberon_new_type_integer(sizeof(int));
+       oberon_define_type(ctx -> world_scope, "INTEGER", ctx -> int_type, 1);
 
-       x -> next = newtype;
-       return newtype; 
+       ctx -> bool_type = oberon_new_type_boolean(sizeof(int));
+       oberon_define_type(ctx -> world_scope, "BOOLEAN", ctx -> bool_type, 1);
 }
 
 static void
-register_default_types(oberon_context_t * ctx)
+oberon_new_intrinsic(oberon_context_t * ctx, char * name, GenerateFuncCallback f, GenerateProcCallback p)
 {
-       static oberon_type_t integer = { "INTEGER", OBERON_TYPE_INTEGER, sizeof(int) };
-       static oberon_type_t boolean = { "BOOLEAN", OBERON_TYPE_BOOLEAN, sizeof(int) };
-
-       ctx -> int_type = oberon_register_global_type_ret(ctx, &integer);
-       ctx -> bool_type = oberon_register_global_type_ret(ctx, &boolean);
+       oberon_object_t * proc;
+       proc = oberon_define_object(ctx -> decl, name, OBERON_CLASS_PROC, 1, 0);
+       proc -> sysproc = 1;
+       proc -> genfunc = f;
+       proc -> genproc = p;
+       proc -> type = oberon_new_type_ptr(OBERON_TYPE_PROCEDURE);
 }
 
-void
-oberon_register_global_type(oberon_context_t * ctx, oberon_type_t * type)
+static oberon_expr_t *
+oberon_make_abs_call(oberon_context_t * ctx, int num_args, oberon_expr_t * list_args)
 {
-       oberon_register_global_type_ret(ctx, type);
+       if(num_args < 1)
+       {
+               oberon_error(ctx, "too few arguments");
+       }
+
+       if(num_args > 1)
+       {
+               oberon_error(ctx, "too mach arguments");
+       }
+
+       oberon_expr_t * arg;
+       arg = list_args;
+
+       oberon_type_t * result_type;
+       result_type = arg -> result;
+       
+       if(result_type -> class != OBERON_TYPE_INTEGER)
+       {
+               oberon_error(ctx, "ABS accepts only integers");
+       }
+
+
+       oberon_expr_t * expr;
+       expr = oberon_new_operator(OP_ABS, result_type, arg, NULL);
+       return expr;
 }
 
 oberon_context_t *
-oberon_create_context()
+oberon_create_context(ModuleImportCallback import_module)
 {
-       oberon_context_t * ctx = malloc(sizeof *ctx);
-       memset(ctx, 0, sizeof *ctx);
+       oberon_context_t * ctx = calloc(1, sizeof *ctx);
 
-       oberon_type_t * types = malloc(sizeof *types);
-       memset(types, 0, sizeof *types);
-       ctx -> types = types;
+       oberon_scope_t * world_scope;
+       world_scope = oberon_open_scope(ctx);
+       ctx -> world_scope = world_scope;
+
+       ctx -> import_module = import_module;
 
        oberon_generator_init_context(ctx);
 
-       register_default_types(ctx);    
+       register_default_types(ctx);
+       oberon_new_intrinsic(ctx, "ABS", oberon_make_abs_call, NULL);
 
        return ctx;
 }
@@ -944,19 +2540,41 @@ oberon_destroy_context(oberon_context_t * ctx)
 }
 
 oberon_module_t *
-oberon_compile_module(oberon_context_t * ctx, const char * code)
+oberon_compile_module(oberon_context_t * ctx, const char * newcode)
 {
-       oberon_module_t * mod = malloc(sizeof *mod);
-       memset(mod, 0, sizeof *mod);
-       oberon_var_t * vars = malloc(sizeof *vars);
-       memset(vars, 0, sizeof *vars);
-       ctx -> mod = mod;
-       ctx -> mod -> vars = vars;
-
-       oberon_init_scaner(ctx, code);
+       const char * code = ctx -> code;
+       int code_index = ctx -> code_index;
+       char c = ctx -> c;
+       int token = ctx -> token;
+       char * string = ctx -> string;
+       int integer = ctx -> integer;
+       oberon_scope_t * decl = ctx -> decl;
+       oberon_module_t * mod = ctx -> mod;
+
+       oberon_scope_t * module_scope;
+       module_scope = oberon_open_scope(ctx);
+
+       oberon_module_t * module;
+       module = calloc(1, sizeof *module);
+       module -> decl = module_scope;
+       module -> next = ctx -> module_list;
+
+       ctx -> mod = module;
+       ctx -> module_list = module;
+
+       oberon_init_scaner(ctx, newcode);
        oberon_parse_module(ctx);
 
-       oberon_generate_code(ctx);
-       return mod;
-}
+       module -> ready = 1;
 
+       ctx -> code = code;
+       ctx -> code_index = code_index;
+       ctx -> c = c;
+       ctx -> token = token;
+       ctx -> string = string;
+       ctx -> integer = integer;
+       ctx -> decl = decl;
+       ctx -> mod = mod;
+
+       return module;
+}